Presentation: Antagonizing RAGE Inhibits Immune Complex Induced IFNα Gene Signature in Human PBMC (2007)

132 Antagonizing RAGE Inhibits Immune Complex Induced IFNα Gene Signature in Human PBMC

Purpose: The pattern recognition receptor, RAGE (receptor for advanced glycation end products) is a multi-ligand type I transmembrane glycoprotein of the immunoglobulin superfamily. RAGE ligands include advanced glycation end products (AGE), amyloid-β peptide, proinflammatory cytokine-like mediators of the S100/calgranulin family, and high mobility group box 1 protein (HMGB1). RAGE has been implicated in several inflammatory disorders and diabetes and recently we reported that HMGB1 and RAGE activate plasmacytoid dendritic cells and B cells in response to DNA and contribute to autoimmune pathogenesis. Furthermore, Increased IFNα levels are associated with systemic lupus erythematosis (SLE) and are believed to play an important role in disease pathology. In this study, we investigated whether RAGE plays a role in the pathogenesis of SLE.
Methods: In our experimental system, PBMC from healthy donors were stimulated for 4h with 50% sera from SLE patients. Total RNA was purified and expression of type I IFN-inducible genes, including DDX58, G1P2, MX1, OAS3, RSAD2, IFIT1, IFI35 were measured by real-time QRT-PCR analysis. Rage antibodies characterization: Anti-huRAGE reactivity was confirmed by ELISA and FACS using soluble RAGE and NSO stably cells transfected with full-length RAGE. Epitope mapping of anti-RAGE mAbs was performed using 293F cells expressing different human RAGE domain deletion mutants. Inhibition of the binding between RAGE and HMGB1/CpG complex was determined by ELISA.
Results: Anti-RAGE mAbs inhibited the IFNα gene signature by ~ 45 % which was comparable to the inhibition by soluble RAGE-Fc (54±11%). Interestingly, these mAbs all bind to RAGE at the C2 domain (plasma-membrane proximal Ig-loop domain). Furthermore, these mAbs also inhibit the binding between RAGE and HMGB1 complexed with CpG DNA.
Conclusion: These results suggest that RAGE and HMGB1 contribute to the activation of the mononuclear cells in SLE, and that antibodies targeting RAGE may present a novel therapeutic approach in the treatment of SLE.

  B. Chen, Full, 3; S. Mao, MedImmune, Inc, 3; Y. Yao, 2250 shares, 1; MedImmune, Inc., 3; C. Chang, MedImmune, Inc, 3; G.P. Sims, MedImmune, Inc, 3; P. Chowdhury, yes, 1; Full-time, 3; L. Audoly, Yes, 1; Yes, 3; R. Herbst, yes, 1; yes, 3; H. Wu, yes, 1; yes, 3; B. Jallal, yes, 1; yes, 1; full, 3; P. Kiener, yes, MedImmune, 1; yes, 3; yes, Synovex, 6; A.J. Coyle, Yes, 1; Yes, 1; Full Time, 3; Yes, 6.